The present invention relates to audio video equipment such as a television receiver, a VTR and audio equipment, and it also relates to a method for producing such an audio video equipment.
Recent audio video equipment such as television receivers, VTRs and audio equipment have been often provided with various functions such as a surround function and a so-called picture-in-picture function (PIP).
The different kinds and numbers of such functions to be added to audio video equipment are used therein even if the equipment is made by the same maker. However, to reduce manufacturing costs, it is desirable to use the same type of a control unit such as a microcomputer for executing and controlling the various functions of the equipment.
Accordingly, for instance, Japanese Patent Application Laid-Open No. HEI 3-250233 shows a system in which a control unit judges the different functions of the equipment, i.e., what functions the various circuits of the audio video equipment are designed or manufactured to possibly attain. The control unit carries out operational controls in response to the possible function.
The system includes a function judgement means such that a diode matrix and the like are connected to predetermined ports of the microcomputer and the function judgement is performed in accordance with ON/OFF information of each port. In other words, the CPU of the microcomputer affects the control operation of the given function on the basis of the presence/absence of the functions. Accordingly, even if the possible functions of the equipment are different from each other, the presence/absence of each function of each equipment is thus judged so that the same type of microcomputer may be used as a control means and the same program may be commonly utilized.
However, in the case where electronic components such as diode matrixes are used as the function judgement means, it is necessary to provide the microcomputer with a terminal of an I/O port for each function. Accordingly, the promotion of versatility in the audio video equipment would inevitably lead to the lack of the terminal number of the I/O ports of an microcomputer. For equipment with the increased number of functions, it is necessary to increase the number of I/O ports for the function judgement corresponding to the increased number of functions. As a result, it would be impossible to use the same type of microcomputers and the production cost is unduly increased.
Furthermore, promotion of versatility would also lead to the enlargement of the diode matrix for the function judgement means, resulting in the increased number of the electronic components or the modification thereof. Accordingly, even if the same type of audio video equipment is made by the same maker, a different manufacture line has to be provided in response to a different function. The larger the number of the functions to be set, the larger the number of the manufacture steps will be.
Thus, in the recent tendency to the promotion of versatility and the increased number of the functions of the equipment, the conventional system in which electronic components such as diode matrixes are used for setting the various functions suffers from problems such that the number of the manufacture steps and the number of the manufacture lines would be increased, resulting in complication of the manufacture steps.